/*
 * Copyright (c) 2001-2008 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Burlap", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Scott Ferguson
 */

package com.caucho.hessian.io;

import java.io.IOException;
import java.io.OutputStream;
import java.util.IdentityHashMap;

/**
 * Output stream for Hessian requests, compatible with microedition Java. It
 * only uses classes and types available in JDK.
 *
 * <p>
 * Since HessianOutput does not depend on any classes other than in the JDK, it
 * can be extracted independently into a smaller package.
 *
 * <p>
 * HessianOutput is unbuffered, so any client needs to provide its own
 * buffering.
 *
 * <pre>
 * OutputStream os = ...; // from http connection
 * HessianOutput out = new HessianOutput(os);
 * String value;
 *
 * out.startCall("hello");  // start hello call
 * out.writeString("arg1"); // write a string argument
 * out.completeCall();      // complete the call
 * </pre>
 */
public class HessianOutput extends AbstractHessianOutput {
	// the output stream/
	protected OutputStream os;
	// map of references
	private IdentityHashMap _refs;
	private int _version = 1;

	/**
	 * Creates a new Hessian output stream, initialized with an underlying
	 * output stream.
	 *
	 * @param os
	 *            the underlying output stream.
	 */
	public HessianOutput(OutputStream os) {
		init(os);
	}

	/**
	 * Creates an uninitialized Hessian output stream.
	 */
	public HessianOutput() {
	}

	/**
	 * Initializes the output
	 */
	public void init(OutputStream os) {
		this.os = os;

		_refs = null;

		if (_serializerFactory == null)
			_serializerFactory = new SerializerFactory();
	}

	/**
	 * Sets the client's version.
	 */
	public void setVersion(int version) {
		_version = version;
	}

	/**
	 * Writes a complete method call.
	 */
	public void call(String method, Object[] args) throws IOException {
		int length = args != null ? args.length : 0;

		startCall(method, length);

		for (int i = 0; i < length; i++)
			writeObject(args[i]);

		completeCall();
	}

	/**
	 * Starts the method call. Clients would use <code>startCall</code> instead
	 * of <code>call</code> if they wanted finer control over writing the
	 * arguments, or needed to write headers.
	 *
	 * <code><pre>
	 * c major minor
	 * m b16 b8 method-name
	 * </pre></code>
	 *
	 * @param method
	 *            the method name to call.
	 */
	public void startCall(String method, int length) throws IOException {
		os.write('c');
		os.write(_version);
		os.write(0);

		os.write('m');
		int len = method.length();
		os.write(len >> 8);
		os.write(len);
		printString(method, 0, len);
	}

	/**
	 * Writes the call tag. This would be followed by the headers and the method
	 * tag.
	 *
	 * <code><pre>
	 * c major minor
	 * </pre></code>
	 *
	 * @param method
	 *            the method name to call.
	 */
	public void startCall() throws IOException {
		os.write('c');
		os.write(0);
		os.write(1);
	}

	/**
	 * Writes the method tag.
	 *
	 * <code><pre>
	 * m b16 b8 method-name
	 * </pre></code>
	 *
	 * @param method
	 *            the method name to call.
	 */
	public void writeMethod(String method) throws IOException {
		os.write('m');
		int len = method.length();
		os.write(len >> 8);
		os.write(len);
		printString(method, 0, len);
	}

	/**
	 * Completes.
	 *
	 * <code><pre>
	 * z
	 * </pre></code>
	 */
	public void completeCall() throws IOException {
		os.write('z');
	}

	/**
	 * Starts the reply
	 *
	 * <p>
	 * A successful completion will have a single value:
	 *
	 * <pre>
	 * r
	 * </pre>
	 */
	public void startReply() throws IOException {
		os.write('r');
		os.write(1);
		os.write(0);
	}

	/**
	 * Completes reading the reply
	 *
	 * <p>
	 * A successful completion will have a single value:
	 *
	 * <pre>
	 * z
	 * </pre>
	 */
	public void completeReply() throws IOException {
		os.write('z');
	}

	/**
	 * Writes a header name. The header value must immediately follow.
	 *
	 * <code><pre>
	 * H b16 b8 foo <em>value</em>
	 * </pre></code>
	 */
	public void writeHeader(String name) throws IOException {
		int len = name.length();

		os.write('H');
		os.write(len >> 8);
		os.write(len);

		printString(name);
	}

	/**
	 * Writes a fault. The fault will be written as a descriptive string
	 * followed by an object:
	 *
	 * <code><pre>
	 * f
	 * &lt;string>code
	 * &lt;string>the fault code
	 *
	 * &lt;string>message
	 * &lt;string>the fault mesage
	 *
	 * &lt;string>detail
	 * mt\x00\xnnjavax.ejb.FinderException
	 *     ...
	 * z
	 * z
	 * </pre></code>
	 *
	 * @param code
	 *            the fault code, a three digit
	 */
	public void writeFault(String code, String message, Object detail)
			throws IOException {
		// hessian/3525
		os.write('r');
		os.write(1);
		os.write(0);

		os.write('f');
		writeString("code");
		writeString(code);

		writeString("message");
		writeString(message);

		if (detail != null) {
			writeString("detail");
			writeObject(detail);
		}
		os.write('z');

		os.write('z');
	}

	/**
	 * Writes any object to the output stream.
	 */
	public void writeObject(Object object) throws IOException {
		if (object == null) {
			writeNull();
			return;
		}

		Serializer serializer;

		serializer = _serializerFactory.getSerializer(object.getClass());

		serializer.writeObject(object, this);
	}

	/**
	 * Writes the list header to the stream. List writers will call
	 * <code>writeListBegin</code> followed by the list contents and then call
	 * <code>writeListEnd</code>.
	 *
	 * <code><pre>
	 * V
	 * t b16 b8 type
	 * l b32 b24 b16 b8
	 * </pre></code>
	 */
	public boolean writeListBegin(int length, String type) throws IOException {
		os.write('V');

		if (type != null) {
			os.write('t');
			printLenString(type);
		}

		if (length >= 0) {
			os.write('l');
			os.write(length >> 24);
			os.write(length >> 16);
			os.write(length >> 8);
			os.write(length);
		}

		return true;
	}

	/**
	 * Writes the tail of the list to the stream.
	 */
	public void writeListEnd() throws IOException {
		os.write('z');
	}

	/**
	 * Writes the map header to the stream. Map writers will call
	 * <code>writeMapBegin</code> followed by the map contents and then call
	 * <code>writeMapEnd</code>.
	 *
	 * <code><pre>
	 * Mt b16 b8 (<key> <value>)z
	 * </pre></code>
	 */
	public void writeMapBegin(String type) throws IOException {
		os.write('M');
		os.write('t');
		printLenString(type);
	}

	/**
	 * Writes the tail of the map to the stream.
	 */
	public void writeMapEnd() throws IOException {
		os.write('z');
	}

	/**
	 * Writes a remote object reference to the stream. The type is the type of
	 * the remote interface.
	 *
	 * <code><pre>
	 * 'r' 't' b16 b8 type url
	 * </pre></code>
	 */
	public void writeRemote(String type, String url) throws IOException {
		os.write('r');
		os.write('t');
		printLenString(type);
		os.write('S');
		printLenString(url);
	}

	/**
	 * Writes a boolean value to the stream. The boolean will be written with
	 * the following syntax:
	 *
	 * <code><pre>
	 * T
	 * F
	 * </pre></code>
	 *
	 * @param value
	 *            the boolean value to write.
	 */
	public void writeBoolean(boolean value) throws IOException {
		if (value)
			os.write('T');
		else
			os.write('F');
	}

	/**
	 * Writes an integer value to the stream. The integer will be written with
	 * the following syntax:
	 *
	 * <code><pre>
	 * I b32 b24 b16 b8
	 * </pre></code>
	 *
	 * @param value
	 *            the integer value to write.
	 */
	public void writeInt(int value) throws IOException {
		os.write('I');
		os.write(value >> 24);
		os.write(value >> 16);
		os.write(value >> 8);
		os.write(value);
	}

	/**
	 * Writes a long value to the stream. The long will be written with the
	 * following syntax:
	 *
	 * <code><pre>
	 * L b64 b56 b48 b40 b32 b24 b16 b8
	 * </pre></code>
	 *
	 * @param value
	 *            the long value to write.
	 */
	public void writeLong(long value) throws IOException {
		os.write('L');
		os.write((byte) (value >> 56));
		os.write((byte) (value >> 48));
		os.write((byte) (value >> 40));
		os.write((byte) (value >> 32));
		os.write((byte) (value >> 24));
		os.write((byte) (value >> 16));
		os.write((byte) (value >> 8));
		os.write((byte) (value));
	}

	/**
	 * Writes a double value to the stream. The double will be written with the
	 * following syntax:
	 *
	 * <code><pre>
	 * D b64 b56 b48 b40 b32 b24 b16 b8
	 * </pre></code>
	 *
	 * @param value
	 *            the double value to write.
	 */
	public void writeDouble(double value) throws IOException {
		long bits = Double.doubleToLongBits(value);

		os.write('D');
		os.write((byte) (bits >> 56));
		os.write((byte) (bits >> 48));
		os.write((byte) (bits >> 40));
		os.write((byte) (bits >> 32));
		os.write((byte) (bits >> 24));
		os.write((byte) (bits >> 16));
		os.write((byte) (bits >> 8));
		os.write((byte) (bits));
	}

	/**
	 * Writes a date to the stream.
	 *
	 * <code><pre>
	 * T  b64 b56 b48 b40 b32 b24 b16 b8
	 * </pre></code>
	 *
	 * @param time
	 *            the date in milliseconds from the epoch in UTC
	 */
	public void writeUTCDate(long time) throws IOException {
		os.write('d');
		os.write((byte) (time >> 56));
		os.write((byte) (time >> 48));
		os.write((byte) (time >> 40));
		os.write((byte) (time >> 32));
		os.write((byte) (time >> 24));
		os.write((byte) (time >> 16));
		os.write((byte) (time >> 8));
		os.write((byte) (time));
	}

	/**
	 * Writes a null value to the stream. The null will be written with the
	 * following syntax
	 *
	 * <code><pre>
	 * N
	 * </pre></code>
	 *
	 * @param value
	 *            the string value to write.
	 */
	public void writeNull() throws IOException {
		os.write('N');
	}

	/**
	 * Writes a string value to the stream using UTF-8 encoding. The string will
	 * be written with the following syntax:
	 *
	 * <code><pre>
	 * S b16 b8 string-value
	 * </pre></code>
	 *
	 * If the value is null, it will be written as
	 *
	 * <code><pre>
	 * N
	 * </pre></code>
	 *
	 * @param value
	 *            the string value to write.
	 */
	public void writeString(String value) throws IOException {
		if (value == null) {
			os.write('N');
		} else {
			int length = value.length();
			int offset = 0;

			while (length > 0x8000) {
				int sublen = 0x8000;

				// chunk can't end in high surrogate
				char tail = value.charAt(offset + sublen - 1);

				if (0xd800 <= tail && tail <= 0xdbff)
					sublen--;

				os.write('s');
				os.write(sublen >> 8);
				os.write(sublen);

				printString(value, offset, sublen);

				length -= sublen;
				offset += sublen;
			}

			os.write('S');
			os.write(length >> 8);
			os.write(length);

			printString(value, offset, length);
		}
	}

	/**
	 * Writes a string value to the stream using UTF-8 encoding. The string will
	 * be written with the following syntax:
	 *
	 * <code><pre>
	 * S b16 b8 string-value
	 * </pre></code>
	 *
	 * If the value is null, it will be written as
	 *
	 * <code><pre>
	 * N
	 * </pre></code>
	 *
	 * @param value
	 *            the string value to write.
	 */
	public void writeString(char[] buffer, int offset, int length) throws IOException {
		if (buffer == null) {
			os.write('N');
		} else {
			while (length > 0x8000) {
				int sublen = 0x8000;

				// chunk can't end in high surrogate
				char tail = buffer[offset + sublen - 1];

				if (0xd800 <= tail && tail <= 0xdbff)
					sublen--;

				os.write('s');
				os.write(sublen >> 8);
				os.write(sublen);

				printString(buffer, offset, sublen);

				length -= sublen;
				offset += sublen;
			}

			os.write('S');
			os.write(length >> 8);
			os.write(length);

			printString(buffer, offset, length);
		}
	}

	/**
	 * Writes a byte array to the stream. The array will be written with the
	 * following syntax:
	 *
	 * <code><pre>
	 * B b16 b18 bytes
	 * </pre></code>
	 *
	 * If the value is null, it will be written as
	 *
	 * <code><pre>
	 * N
	 * </pre></code>
	 *
	 * @param value
	 *            the string value to write.
	 */
	public void writeBytes(byte[] buffer) throws IOException {
		if (buffer == null)
			os.write('N');
		else
			writeBytes(buffer, 0, buffer.length);
	}

	/**
	 * Writes a byte array to the stream. The array will be written with the
	 * following syntax:
	 *
	 * <code><pre>
	 * B b16 b18 bytes
	 * </pre></code>
	 *
	 * If the value is null, it will be written as
	 *
	 * <code><pre>
	 * N
	 * </pre></code>
	 *
	 * @param value
	 *            the string value to write.
	 */
	public void writeBytes(byte[] buffer, int offset, int length) throws IOException {
		if (buffer == null) {
			os.write('N');
		} else {
			while (length > 0x8000) {
				int sublen = 0x8000;

				os.write('b');
				os.write(sublen >> 8);
				os.write(sublen);

				os.write(buffer, offset, sublen);

				length -= sublen;
				offset += sublen;
			}

			os.write('B');
			os.write(length >> 8);
			os.write(length);
			os.write(buffer, offset, length);
		}
	}

	/**
	 * Writes a byte buffer to the stream.
	 *
	 * <code><pre>
	 * </pre></code>
	 */
	public void writeByteBufferStart() throws IOException {
	}

	/**
	 * Writes a byte buffer to the stream.
	 *
	 * <code><pre>
	 * b b16 b18 bytes
	 * </pre></code>
	 */
	public void writeByteBufferPart(byte[] buffer, int offset, int length)
			throws IOException {
		while (length > 0) {
			int sublen = length;

			if (0x8000 < sublen)
				sublen = 0x8000;

			os.write('b');
			os.write(sublen >> 8);
			os.write(sublen);

			os.write(buffer, offset, sublen);

			length -= sublen;
			offset += sublen;
		}
	}

	/**
	 * Writes a byte buffer to the stream.
	 *
	 * <code><pre>
	 * b b16 b18 bytes
	 * </pre></code>
	 */
	public void writeByteBufferEnd(byte[] buffer, int offset, int length)
			throws IOException {
		writeBytes(buffer, offset, length);
	}

	/**
	 * Writes a reference.
	 *
	 * <code><pre>
	 * R b32 b24 b16 b8
	 * </pre></code>
	 *
	 * @param value
	 *            the integer value to write.
	 */
	public void writeRef(int value) throws IOException {
		os.write('R');
		os.write(value >> 24);
		os.write(value >> 16);
		os.write(value >> 8);
		os.write(value);
	}

	/**
	 * Writes a placeholder.
	 *
	 * <code><pre>
	 * P
	 * </pre></code>
	 */
	public void writePlaceholder() throws IOException {
		os.write('P');
	}

	/**
	 * If the object has already been written, just write its ref.
	 *
	 * @return true if we're writing a ref.
	 */
	public boolean addRef(Object object) throws IOException {
		if (_refs == null)
			_refs = new IdentityHashMap();

		Integer ref = (Integer) _refs.get(object);

		if (ref != null) {
			int value = ref.intValue();

			writeRef(value);
			return true;
		} else {
			_refs.put(object, new Integer(_refs.size()));

			return false;
		}
	}

	@Override
	public int getRef(Object obj) {
		Integer value;

		if (_refs == null)
			return -1;

		value = (Integer) _refs.get(obj);

		if (value == null)
			return -1;
		else
			return value;
	}

	/**
	 * Resets the references for streaming.
	 */
	public void resetReferences() {
		if (_refs != null)
			_refs.clear();
	}

	/**
	 * Removes a reference.
	 */
	public boolean removeRef(Object obj) throws IOException {
		if (_refs != null) {
			_refs.remove(obj);

			return true;
		} else
			return false;
	}

	/**
	 * Replaces a reference from one object to another.
	 */
	public boolean replaceRef(Object oldRef, Object newRef) throws IOException {
		Integer value = (Integer) _refs.remove(oldRef);

		if (value != null) {
			_refs.put(newRef, value);

			return true;
		} else
			return false;
	}

	/**
	 * Prints a string to the stream, encoded as UTF-8 with preceeding length
	 *
	 * @param v
	 *            the string to print.
	 */
	public void printLenString(String v) throws IOException {
		if (v == null) {
			os.write(0);
			os.write(0);
		} else {
			int len = v.length();
			os.write(len >> 8);
			os.write(len);

			printString(v, 0, len);
		}
	}

	/**
	 * Prints a string to the stream, encoded as UTF-8
	 *
	 * @param v
	 *            the string to print.
	 */
	public void printString(String v) throws IOException {
		printString(v, 0, v.length());
	}

	/**
	 * Prints a string to the stream, encoded as UTF-8
	 *
	 * @param v
	 *            the string to print.
	 */
	public void printString(String v, int offset, int length) throws IOException {
		for (int i = 0; i < length; i++) {
			char ch = v.charAt(i + offset);

			if (ch < 0x80)
				os.write(ch);
			else if (ch < 0x800) {
				os.write(0xc0 + ((ch >> 6) & 0x1f));
				os.write(0x80 + (ch & 0x3f));
			} else {
				os.write(0xe0 + ((ch >> 12) & 0xf));
				os.write(0x80 + ((ch >> 6) & 0x3f));
				os.write(0x80 + (ch & 0x3f));
			}
		}
	}

	/**
	 * Prints a string to the stream, encoded as UTF-8
	 *
	 * @param v
	 *            the string to print.
	 */
	public void printString(char[] v, int offset, int length) throws IOException {
		for (int i = 0; i < length; i++) {
			char ch = v[i + offset];

			if (ch < 0x80)
				os.write(ch);
			else if (ch < 0x800) {
				os.write(0xc0 + ((ch >> 6) & 0x1f));
				os.write(0x80 + (ch & 0x3f));
			} else {
				os.write(0xe0 + ((ch >> 12) & 0xf));
				os.write(0x80 + ((ch >> 6) & 0x3f));
				os.write(0x80 + (ch & 0x3f));
			}
		}
	}

	public void flush() throws IOException {
		if (this.os != null)
			this.os.flush();
	}

	public void close() throws IOException {
		if (this.os != null)
			this.os.flush();
	}
}
